In the univariate analysis of the training group of CRC patients after first-line chemotherapy, significant differences were observed between the myelosuppression and non-myelosuppression groups in terms of age, gender, smoking, diabetes, body surface area(BSA), body mass index(BMI), tumor staging, tumor location, hepatic metastasis, lung metastasis, albumin(ALB), carcinoembryonic antigen(CEA), and the number of chemotherapy cycles. This evidence concerns the gene CEACAM5 and diabetes mellitus.